SQL 2012 :: Clustering AlwaysOn - Primary And Secondary Replica
Apr 11, 2014Looking for info on ole/requirement of primary and secondary replica under SQL Server 2012 AlwaysOn.
View 4 RepliesLooking for info on ole/requirement of primary and secondary replica under SQL Server 2012 AlwaysOn.
View 4 RepliesI was working on a job to send me info each morning about database file free space and was noticing some odd things when looking at the log file VLFs for one of my databases in an AlwaysOn availability group.When I run DBCC LOGINFO on the secondary replica for this database, I get what I expect and most VLFs have a status of 0 (indicating the VLFs are reusable or unused). When I run DBCC LOGINFO on the primary replica, all of the VLFs have a status of 2 (active or recoverable).
Since log backups on the secondary replica in AlwaysOn still truncate the log in the primary replica, I would expect that the VLFs in the primary replica would also be mostly in a reusable or unused state. My log file sizes are the same size on each server and my backups are completing successfully. what might be causing the VLFs on the primary replica to have a status of 2 in DBCC LOGINFO when taking log backups from the secondary replica?
I have 2 SQL Server replicas configured on SQL Server 2012 AlwaysOn. e.g. SQL1 & SQL2.
I have configured backup job on both SQL Server with the following statement. and the job occurs every 10 minutes.
•declare @DBNAME sysname,@sqlstr varchar(500)
set @DBNAME = 'dba'
IF (sys.fn_hadr_backup_is_preferred_replica(@DBNAME)=0)
BEGIN
--Select 'This is not the preferred replica, exiting with success';
[Code] ...
I turned off SQL2 for Windows maintenance. So there is only SQL1 is online. Afterwards. I checked the backup folder and didn't see any new backup files was created after SQL2 was offline. I rerun the job. It still doesn't backup database on the Primary Replica. Then I searched on SQL Server Book online. It says
Prefer Secondary
Specifies that backups should occur on a secondary replica except when the primary replica is the only replica online. In that case, the backup should occur on the primary replica. This is the default option.
According to what it says, it should backup on the Primary Replica.
I have an AlwaysOn Availability group configured between 2 nodes (Synchronous)
Automatic failover was working fine until recently
I can failover between the nodes manually but automatic failover doesn't seem to be working. In my earlier test, I would shut down the SQL Service on the primary and within seconds, the secondary replica would take over. Recently I have performed the same test and the secondary replica enters the resolving state and the DB in unavailable.
I have tried everything here: [URL] ....
The only change I made was changing the availability mode from Synchronous to Asynchronous - Could that be the cause?
What happens when an automatic failover occurs, in a two server AlwaysOn Availability Group configuration, where the secondary replica is configured as read-only?
Will it only allow read-only connections, or will it become read-write and can accept INSERT, UPDATES and DELETES when assigned the new role as Primary?
Is it correct that adding a third server/node, that just acts as passive and should be used for automatic failover, to support true HADR, would NOT need another license .. and that licenses would only be required for the previous Primary and Secondary (Read-Only) replicas?
I have a SP that runs on the primary in 18 min and 45 min on the secondary( poorly written cursor,trying to fix it).Both machines are Exactly the same.I ran them in the middle of the night when no one was on the Sec. Node as we use it for reporting.
PLE: 7,000+
AVG Disk sec/write below .01
AVG Disk sec/read below .01
CPU below 5%
both machines set a max dop 4
As per our client requirement we want to set synchronization time from primary replica to secondary replica after 20 minutes. Is it possible in MSSQL AlwaysOn Availability Groups in SQL Server 2012?
View 6 Replies View Relatedin my secondary server the database which is in restoring state , when i checked in always on dash board "This secondary database is not joined to the availability group" ,
View 3 Replies View RelatedSQL is generating dump every 1 min with error
EXCEPTION_ACCESS_VIOLATION reading address 0000000000000020 at
Server is running SP2 CU2.
Environment:-
Windows 2012 R2,
SQL 2012 (Primary Replica)
SQL 2012 (Seondary Replica)
SQL 2012 (Secondary Replica over WAN site)
There are database replicating on three SQL servers. WAN line is having performance issue because of limited bandwidth I have to remove SQL secondary replica over WAN site temporarily and add it again later when the WAN line is upgraded with between bandwidth What is the best practice to remove secondary replica and replicating database and add later from SQL management studio without interruptions on databases?
How can we change the backup replica in Always on Cluster. I am not able to take backup because of this.
View 7 Replies View RelatedAfter failing over to the DR replica. All databases are out of sync. DR replicas were setup as async the other 2 are set up as sync. Is this by design. No data has been updated to any of these as they are test dbs. So all dbs should be the same, no data loss.
View 0 Replies View RelatedWhile configuring SQL Server 2012 Cluster with Always on, why do we need two secondary replicas.
The attached link will describe the actual query. [URL] ....
Setting up a test AlwaysOn Availability Group for one database.
However, whenever I restore the database to the replica server and join it, it ends up with my user account as the owner of the database.
Obviously I do not want a user account as the database owner, but since it is read-only I cannot modify it directly. If I were able to fail the AG over to the replica, I could change the owner then, but I cannot due to business requirements. this AG is to essentially serve as a replacement to log shipping.
I tried doing the backups and restores using EXECUTE AS login = 'sa', and yet it still shows up as my user account.
In always on under availability group server name properties can see the option Readable Secondary. In that for secondary server the Readable Secondary Option is YES and for Primary it is Read-Intent. I believe Read-Intent allows only read only connections and YES allows all user connections.
View 0 Replies View RelatedIn always on under availability group server name properties can see the option Readable Secondary. In that for secondary server the Readable Secondary Option is YES and for Primary it is Read-Intent. I believe Read-Intent allows only read only connections and YES allows all user connections.
What exactly it means for the primary and secondary?
Secondary replica database(setup in async mode) of AlwaysON went in "restricted mode" during weekly reindex operation.
So I have tried below steps
1) Executed following statement on the same secondary replica database where the issue exists
alter database <DBNAME> set multi_user with rollback immediate
but it failed with the error saying "The operation cannot be performed on database "dbname" because it is involved in a database mirroring session or an availability group. Some operations are not allowed on a database that is participating in a database mirroring session or in an availability group. ALTER DATABASE statement failed."
2) Primary database is multi_user but still tried following command on primary replia database(thinking it will replicate)
alter database <DBNAME> set multi_user
but no luck. The secondary alwaysON database shows (synchronizing) as the alwaysON is set in async mode but the command doesn't replicate across secondary
so we are left with the only option to re-setup alwaysON but I want to avoid it as database size is huge..
any other options or am I missing anything?
MCP,MCDBA(SQL 2000),MCTS(SQL 2005),MCITP(SQL 2005)
What are differences between always on and SQL Server Clustering
View 1 Replies View RelatedGive the Advantages Over SQL SERVER Always on over Clustering....
View 4 Replies View RelatedI know now that AlwaysOn feature HAS to be installed/configured on a Windows Clustering environment, BUT the secondary replicas, like the Disaster recovery replica residing in a different Data Center HAS to be also in a Windows Clustering environment or can it reside on a SINGLE SQL Server INSTANCE?.
View 6 Replies View Related"If we fail over a SQL AG group on a failover cluster from one node to another making the secondary the new primary, is there any reason why we would have to fail it back over to the old primary node?"
View 2 Replies View RelatedIn my environment always on is there. Today I observed that primary server fail over to secondary server .now the secondary server acting as primary role.
Can I know when is fail over is happened and who did the fail over. Is there any script to find this?
In always on docs in msdn they mention only about backup of secondary.. explain the backup of primary or how logs are managed in primary database. My doubt is a normal database in full recovery mode the log file will grow if we didnt take proper log backup,how the same is managed in primary in Always On.
View 2 Replies View RelatedSecondary server is offline due to a hardware issue and the log files are growing on Primary sever for availability databases. The log drive is running out of space. How can I stop the log growth for the primary databases?
View 4 Replies View RelatedI have a scenario where a customer is going to be using Log Shipping to the DR site; however, we need to maintain the normal backup strategy on the current system. (i.e. Nightly Full, Every 6 Hour Differential and Hourly Transaction Log backup)I know how to setup Transaction Log Shipping and Fail-over to DR and backup but now the local backup strategy is going to be an issue. I use the [URL] .... maintenance solution currently.
Is it even possible to do regular backups locally keeping data integrity for your backup strategy with Transaction Log Shipping enabled?
MSDN states the following on: Readable Secondary Replicas (AlwaysOn Availability Groups) for SQL Server 2014:
Limitations and Restrictions:
Change tracking and change data capture are not supported on secondary databases that belong to a readable secondary replica:
Change tracking is explicitly disabled on secondary databases.
Change data capture can be enabled on a secondary database, but this is not supported.
This confuses me: You can not track the changes. However you can enable CDC?
The scenario I am trying to achieve is to use SSIS CDC components on an asynchronous secondary replica. Is this possible? If not what would be other viable approaches?
is there any limition in AlwayOn to add database in secondary replica?
View 2 Replies View RelatedAssume if i have a connection(Application intent readonly) starts with reading, writing and again reading data for a report. how it will works in SQL 2014 Always availability on?
View 3 Replies View RelatedWe are not able to failover the AG to secondary replica. The process gets timed out and AG goes to resolving mode. Had to reboot the box in order to switch the AG back to primary node. We even rebuilt the whole AG from scratch but the issue remains.
Failed to bring availability group 'xxxx' online. The operation timed out. Verify that the local Windows Server Failover Clustering (WSFC) node is online. Then verify that the availability group resource exists in the WSFC cluster. If the problem persists, you might need to drop the availability group and create it again. [SQLSTATE 42000] (Error 41131). The step failed.
Not much information is available in the logs.
Version : sql server 2014 sp1
I was hoping for some information regarding table triggers. We have databases that are part of an AlwaysOn availability group on SQL Server 2012. Some of the tables have table triggers defined. There are both types of triggers, INSTEAD OF and AFTER INSERT, etc.
From my understanding of how secondary read-only replicas work, I am assuming that these triggers have no impact at all when the database is a read-only secondary replica and they only fire when the database is the primary read-write database.
However, after doing a search on the internet, I have not been able to find a definitive source of information.
We have a reporting database which is refreshed daily from prod backup and later creating new tables/views/indexes as part of the refresh job. Is there a better approach we can implement in sql 2012/2014 for this scenario since we are planning to migrate to sql2014.
View 5 Replies View RelatedI am working on adding DBs to the AG but for some reason I am getting this error.
"Joining DB on secondary replica resulted in error"
Msg: The remote copy of the database is not recovered far enough to enable DB mirroring or to join AG. Missing log records have to be applied to the remote DB by restoring the current log backups" Which I did. I took the log backup of DB1, restored it on DB2 with no recovery, but still I am getting the same error.
I am trying to implement a read only replica to move much of the data read for an application to the secondary replica. Initially I had the the primary and secondary set to asynchronous commit. QA brought up an issue with creating entities from the application because after the creation of an entity the application turns around and repopulates the entire aggregate object. Well it seems that the application was reading the secondary replica before the data had been committed. Although I understand the issues that synchronous commits can cause, I went ahead and made the change as I expected it to fix the issue. After changing the primary replica to synchronous we still had the error, so I also changed the secondary although that makes no since, but the issue remains.
View 5 Replies View Related